Edge computing system and main satellite

Abstract

To provide an edge computing system based on LEO constellation, which enables each satellite and a ground facility to quickly communicate with an edge server included in a main satellite.SOLUTION: An edge computing system 11 comprises: a plurality of satellites 30 flying on a target track. Each satellite 30 includes a first communication device that communicates with the satellites 30 located front and rear in an advancing direction and a second communication device that communicates with a ground facility 90. The satellites 30 form an annular communication network. One of the satellites 30 is a main satellite 40 provided with a computer 41 and an edge server 42 that stores track information of each satellite 30. The computer 41 generates achievement information, and derives time TmO of passage, above the ground facility 90, of a satellite m passing above the ground facility 90. The main satellite 40 transmits the achievement information through the annular communication network to the satellite m. The satellite m transmits the achievement information to the ground facility 90.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present disclosure relates to an edge computing system and a primary satellite. [Background technology]

[0002] Latency associated with long-distance communications using GEO (Geostationary Earth Orbit) satellites has been an issue. In recent years, development of communications satellite systems using mega-constellations consisting of LEO (Low Earth Orbit) satellites has been progressing. However, in the current communications satellite systems, individual satellites communicate using the bent-pipe method, but inter-satellite communications are not implemented. Therefore, the addition of inter-satellite communications functionality to these communications satellite systems is eagerly awaited. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 9,647,749 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a communications satellite system using a LEO constellation consisting of LEO satellites that perform optical inter-satellite communications with satellites located on the left, right, and front and rear sides. However, this communications satellite system has the problem that orbits are swapped at the southern and northern ends of the orbital plane, resulting in communication interruptions occurring twice per orbit in communications with satellites located on the left and right that fly in adjacent orbits. Furthermore, as a result of this problem, there is the problem of needing to establish high-precision optical axis alignment technology to establish a line twice per orbit via optical wireless communication, which also results in significant loss of time.

[0005] The present disclosure aims to enable each satellite and ground equipment in an edge computing system using a LEO constellation to quickly communicate with an edge server equipped on the main satellite. [Means for solving the problem]

[0006] The edge computing system according to the present disclosure includes: An edge computing system consisting of a plurality of satellites flying in a target orbital plane, Each of the plurality of satellites is designated as a target satellite, and the target satellite is a satellite flying in the target orbital plane, and the target satellite is equipped with a first communication device that communicates with satellites located ahead and behind the target satellite in the direction of travel, and a second communication device that communicates with ground equipment installed on the ground, the plurality of satellites form a circular communication network, any one of the plurality of satellites is a primary satellite having a computer and an edge server storing orbital information of each of the plurality of satellites; The computer Generate result information by performing an analysis process; Selecting a satellite that passes over the ground facility from among the plurality of satellites as a satellite m based on the orbit information stored in the edge server, and deriving a time Tm0 at which the satellite m passes over the ground facility; The main satellite transmits the result information to the satellite m through the ring communication network; The satellite m transmits the result information to the ground equipment at the time Tm0. [Effects of the Invention]

[0007] The edge computing system according to the present disclosure may be based on a LEO constellation. Also, in the present disclosure, the edge computing system includes a plurality of satellites flying in a target orbital plane. The plurality of satellites form a circular communication network. One of the plurality of satellites is a main satellite, which includes a computer and an edge server storing orbital information for each of the plurality of satellites. The computer generates result information by executing an analysis process, and based on the orbital information stored in the edge server, selects a satellite passing over a ground facility from the plurality of satellites as satellite m, and derives the time Tm0 at which satellite m will pass over the ground facility. The main satellite transmits the result information to satellite m via the circular communication network. Satellite m transmits the result information to the ground facility at time Tm0. Therefore, according to the present disclosure, in an edge computing system using a LEO constellation, each satellite and ground equipment can quickly communicate with the edge server equipped on the main satellite. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an outline of a communications satellite system 10 according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating a ring communication network according to a first embodiment. [Figure 3] FIG. 2 is a diagram showing an example of the hardware configuration of a satellite 30 according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing an example of the hardware configuration of the ground equipment 90 according to the first embodiment. [Figure 5] 3 is a diagram for explaining an example of the operation of the communications satellite system 10 according to the first embodiment. [Figure 6] FIG. 1 is a diagram showing a state in which a ring communication network is formed. [Figure 7] A diagram showing communication with satellites located in front, behind, on both sides. [Figure 8] A diagram explaining the left-right swap of satellites. [Figure 9] FIG. 2 is a diagram illustrating inter-orbit communication according to the first embodiment. [Figure 10]FIG. 2 is a diagram illustrating inter-orbit communication according to the first embodiment. [Figure 11] These diagrams show how the rotation of the Earth and the rotation of the orbital plane of an inclined orbit satellite are not synchronized. (a) is a specific example of what happens at 06:00, and (b) is a specific example of what happens at 12:00. [Figure 12] FIG. 10 is a diagram showing an example of the hardware configuration of a ground facility 90 according to a modified example of the first embodiment. [Figure 13] FIG. 10 is a diagram showing an example of the configuration of an edge computing system 11 according to a second embodiment. [Figure 14] FIG. 10 is a diagram illustrating an example of the operation of the edge computing system 11 according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the description of the embodiments and drawings, the same elements and corresponding elements are given the same reference numerals. The description of elements given the same reference numerals will be omitted or simplified as appropriate. Arrows in the drawings mainly indicate the flow of data or the flow of processing. Furthermore, "unit" may be read as "circuit," "step," "procedure," "processing," or "circuitry" as appropriate. In this specification, an artificial satellite may also be referred to simply as a satellite. In addition, in the description of the embodiments, directions or positions such as "upper," "lower," "left," "right," "front," "rear," "top," and "bottom" may be indicated. These notations are used merely for the convenience of explanation and do not limit the arrangement or orientation of components such as devices, appliances, or parts.

[0010] Embodiment 1 Hereinafter, this embodiment will be described in detail with reference to the drawings.

[0011] ***Configuration Description*** FIG. 1 shows an outline of a communications satellite system 10 according to this embodiment. As shown in this figure, the communications satellite system 10 comprises a satellite constellation 20 and ground equipment 90 .

[0012] The satellite constellation 20 is composed of multiple orbital planes, typically an inclined orbit satellite constellation in which each satellite 30 orbits in an inclined orbit. That is, the communication satellite system 10 is composed of multiple orbital planes. The satellite constellation 20 may be a LEO (Low Earth Orbit) constellation. Furthermore, the azimuth components of the normal vectors to each of the multiple orbital planes are dispersed in the longitude direction. When each of the multiple orbital planes is considered a target orbital plane, the target orbital plane corresponds to an inclined orbit, and multiple satellites 30 fly on the target orbital plane. Furthermore, when each satellite 30 flying on the target orbital plane is considered a target satellite, the target satellite includes a first communication device, a second communication device, and a third communication device. The first communication device communicates with the satellite 30 flying on the orbital plane in which the target satellite flies, and is located both ahead and behind the target satellite in the direction of flight. The second communication device communicates with ground equipment 90 installed on the ground. The third communication device communicates with a satellite 30 flying in another orbital plane in the vicinity of an intersection formed in a plan view by the orbital plane in which the target satellite is flying and another orbital plane that is different from the orbital plane in which the target satellite is flying. At least two of the first communication device, the second communication device, and the third communication device may be integrally configured as appropriate. Note that the vicinity of the intersection is a region surrounding the intersection including the intersection. The range of the vicinity of the intersection may be determined as appropriate. In addition, in a target orbital plane, a plurality of satellites 30 flying in the target orbital plane form a circular communication network. Figure 2 is a diagram illustrating the circular communication network formed by a plurality of satellites 30. As shown in Figure 2, a circular communication network is formed in each of the plurality of orbital planes by communication between adjacent satellites 30 on the same orbit. Examples of satellite constellations 20 are disclosed in [Reference 1] and [Reference 2]. Communications satellite system 10 may include the functionality disclosed in these references. Satellite constellation 20 may also be a mega-constellation.

[0013] [Reference 1] Patent Publication No. 2021-054167 [Reference 2] Patent Publication No. 2021-070342

[0014] The ground equipment 90 includes a ground-side communication device 810 and a satellite control device 91 , and controls the satellite constellation 20 by communicating with each satellite 30 . The satellite control device 91 is a computer that generates various commands for controlling each satellite 30, and includes hardware such as a processing circuit and an input / output interface. The processing circuit generates the various commands. An input device and an output device are connected to the input / output interface. The satellite control device 91 is connected to the ground communication device 810 via the input / output interface. The ground communication device 810 communicates with each satellite 30. Specifically, the ground communication device 810 transmits various commands to each satellite 30.

[0015] 3 shows an example of the hardware configuration of the satellite 30. The hardware configuration of the satellite 30 will be described with reference to FIG. The satellite 30 includes a satellite control device 31, a communication device 32, a propulsion device 33, an attitude control device 34, and a power supply device 35. The satellite 30 may include components that realize various other functions, but Fig. 3 will explain the satellite control device 31, the communication device 32, the propulsion device 33, the attitude control device 34, and the power supply device 35.

[0016] The satellite control device 31 is a computer that controls the propulsion devices 33 and the attitude control device 34, and includes a processing circuit. Specifically, the satellite control device 31 controls the propulsion devices 33 and the attitude control device 34 in accordance with various commands transmitted from the ground facility 90 and the like. The communication device 32 is a device that executes communication with the outside of the satellite 30. The communication device 32 is also a general term for the first communication device, the second communication device, and the third communication device. The propulsion device 33 is a device that provides thrust to the satellite 30, changing the speed of the satellite 30. The attitude control device 34 is a device for controlling attitude elements such as the attitude of the satellite 30, its angular velocity, and line of sight. The attitude control device 34 changes each attitude element to a desired direction. Alternatively, the attitude control device 34 maintains each attitude element in a desired direction. The attitude control device 34 includes an attitude sensor, an actuator, and a controller. The attitude sensor is a device such as a gyroscope, an Earth sensor, a sun sensor, a star tracker, a thruster, and a magnetic sensor. The actuator is a device such as an attitude control thruster, a momentum wheel, a reaction wheel, and a control moment gyro. The controller controls the actuator according to measurement data from the attitude sensor or various commands from the ground equipment 90, etc. The power supply unit 35 includes devices such as solar cells, batteries, and a power control device, and supplies power to each device mounted on the satellite 30.

[0017] The processing circuit provided in the satellite control device 31 will now be described. The processing circuit may be dedicated hardware or a processor that executes a program stored in memory. In the processing circuit, some functions may be realized by dedicated hardware and the remaining functions may be realized by software or firmware. In other words, the processing circuit can be realized by hardware, software, firmware, or a combination of these. Specifically, the dedicated hardware may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination of these. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field Programmable Gate Array.

[0018] 4 shows an example of the hardware configuration of the ground facility 90. The ground facility 90 communicates with the satellite 30. The ground facility 90 is connected to a ground-side communication device 810, and communicates with the satellite 30 via the ground-side communication device 810. The ground facility 90 may be a mobile terminal.

[0019] The ground equipment 90 includes a processor 710 as well as other hardware such as a main memory device 720, an auxiliary memory device 730, an input interface 740, an output interface 750, and a communication interface 760. In Fig. 4, the interfaces are denoted as IF. The processor 710 is connected to other hardware via a signal line 770 and controls this other hardware.

[0020] The ground equipment 90 includes a control unit 711 as a functional element. The functions of the control unit 711 are realized by hardware or software. The control unit 711 executes processing in accordance with instructions from a communications satellite program.

[0021] ***Explanation of Operation*** The operating procedure of the communications satellite system 10 corresponds to a communications satellite method. The program that realizes the operation of the communications satellite system 10 corresponds to a communications satellite program. The communications satellite program is also a general term for programs that run in each device included in the communications satellite system 10. The communications satellite program may be recorded on a computer-readable non-volatile recording medium. Specific examples of the non-volatile recording medium include an optical disk or a flash memory. The communications satellite program may be provided as a program product.

[0022] <Operation Example 1 According to Embodiment 1> 5 is a diagram for explaining this operation example, which will be described with reference to FIG.

[0023] (1) Communication with ground equipment A first receiving satellite, which is a satellite 30 flying in a first orbital plane, receives communication data, which is data transmitted by the first ground facility 90, in the airspace above the first ground facility 90. The first orbital plane is an orbital plane that passes over the first ground facility 90 and is any one of a plurality of orbital planes. The airspace above the ground facility 90 is an area in which the satellite 30 can communicate with the ground facility 90.

[0024] (2) Same-orbital plane communication The first receiving satellite shares communication data with another satellite 30 flying in the first orbital plane through a circular communication network formed in the first orbital plane.

[0025] (3) Inter-orbit communication Any one of the plurality of satellites 30 flying in the first orbital plane transmits communication data to a second receiving satellite, which is a satellite 30 flying in the second orbital plane, near the intersection formed by the first orbital plane and the second orbital plane in a plan view. The second orbital plane is an orbital plane that passes above the second ground facility 90 and is any orbital plane other than the first orbital plane among the plurality of orbital planes.

[0026] (4) Same-orbital plane communication The second receiving satellite shares communication data with another satellite 30 flying in the second orbital plane through a circular communication network formed in the second orbital plane.

[0027] (5) Communication with ground equipment Any one of the plurality of satellites 30 flying in the second orbital plane transmits communication data to the second ground facility 90 while in the sky above the second ground facility 90 .

[0028] In recent years, there has been an increase in plans to build communication satellite networks using large-scale satellite groups known as megaconstellations. In one example of a megaconstellation, each satellite in each orbital plane communicates with the satellites in front and behind it, forming a circular communication network. Furthermore, each satellite in each orbital plane communicates with satellites in adjacent orbital planes located to the left and right of each satellite in that orbital plane. As a result, a mesh communication network is built in which each satellite communicates with a total of four satellites located in front, behind, left, and right. Figure 6 shows how a circular communication network is formed. Figure 7 shows how a satellite communicates with a total of four satellites located in front, behind, left, and right. However, in order to maintain communication with adjacent orbits, pointing control of the communication device is required. Furthermore, orbits swap at the northernmost and southernmost ends of the orbital plane, making it difficult to continue a single communication. Figure 8 shows how the swap occurs at the northernmost end of the orbital plane. In Figure 8, a satellite flying in orbit 2 is located to the right of the direction of travel of a satellite flying in orbit 1 until it reaches the northernmost end. Meanwhile, after it reaches the northernmost end, a satellite flying in orbit 2 is located to the left of the direction of travel of a satellite flying in orbit 1.

[0029] In an inclined orbit satellite constellation, there are two intersections between two orbital planes with different normal vectors. Therefore, if a satellite 30 flying in one orbital plane communicates with a satellite 30 flying in another orbital plane with a normal vector different from that of the first orbital plane via inter-orbital communications when both the satellite 30 flying in the first orbital plane and the satellite 30 flying in the other orbital plane pass near one of the intersections formed by the first orbital plane and the other orbital plane in a planar view, the two satellites 30 can share satellite information in both the first orbital plane and the other orbital plane. Similarly, each satellite 30 can share satellite information in all orbital planes. FIG. 9 is a diagram for explaining inter-orbital communication, showing a specific example in which a satellite 30 flying in one orbital plane communicates with satellites 30 flying in all other orbital planes. FIG. 10 is a diagram for explaining inter-orbital communication, showing a specific example in which a satellite 30 flying in each orbital plane communicates with satellites 30 flying in the other two orbital planes.

[0030] The inter-satellite communication that occurs when satellite 30 passes near the intersection of the orbital planes is not long-distance communication such as communication between adjacent orbits, but short-distance communication, and therefore can be realized by a simple communication device using, for example, an omnidirectional antenna or a fixed antenna. Furthermore, since there are many combinations of nodes for which communication is required to share satellite information on all orbital planes, each satellite 30 does not need to perform proximity communication at all nodes of its inclined orbit, but only needs to perform proximity communication near each node belonging to a reasonably selected combination of nodes. As a specific example, consider a case where a first ground facility 90 communicates with a second ground facility 90 via a communications satellite system 10. In this case, the rotation of the Earth and the rotation of the orbital plane of the inclined orbit satellite are not synchronized. Therefore, the orbital plane to which the satellite 30 flying above the first ground facility 90 belongs at time T0 is limited. Figure 11 shows a situation in which the rotation of the Earth and the rotation of the orbital plane of the inclined orbit satellite are not synchronized. In Figure 11, (a) shows a specific example of the situation at 06:00, and (b) shows a specific example of the situation at 12:00. In Figure 11, the orbital plane in which the satellite 30 flying that can communicate with the ground facility 90 flies, that is, the communicable orbital plane, is not necessarily the same at 06:00 and 12:00. Here, the orbital plane flying above the first ground facility 90 at time T0 is referred to as the first orbital plane. Similarly, the orbital plane flying above the second ground facility 90 at time T0 is referred to as the second orbital plane. When the first and second orbital planes are the same, communication between the first and second ground facilities 90 is possible via a circular communication network. On the other hand, when the first and second orbital planes are different, it is necessary to connect the first circular communication network formed by the first orbital plane with the second circular communication network formed by the second orbital plane. Therefore, the first and second circular communication networks can be connected by communication between satellites 30 passing near one of the intersections formed by the first and second orbital planes in a planar view. Note that when the orbital altitude of the first orbital plane and the orbital altitude of the second orbital plane are the same, there is an intersection between the first and second orbital planes. Therefore, communication can be performed between a satellite 30 belonging to the first orbital plane and a satellite 30 belonging to the second orbital plane near any of the intersections formed by the first and second orbital planes. On the other hand, when the orbits of the first and second orbital planes are elliptical orbits with eccentricities, as a specific example, communication can be performed between a satellite 30 belonging to the first orbital plane and a satellite 30 belonging to the second orbital plane near the point of closest approach between the first and second orbital planes, rather than at the intersection between the first and second orbital planes. In other words, the intersection formed by the first and second orbital planes in a planar view may not be the point where the first and second orbital planes actually intersect, such as the point of closest approach between the first and second orbital planes.

[0031] Here, LEO satellites pass over any given terrestrial facility in a short time. Furthermore, LEO satellites orbit in a sun-synchronous orbit, i.e., the rotation of the orbital plane of the LEO satellite is not synchronized with the Earth's rotation, and therefore the orbital plane in which the LEO satellite passes over the terrestrial facility changes from moment to moment. Therefore, in order to communicate from one terrestrial facility to another using conventional technology, it is necessary to create an operation plan in advance by searching for the orbital planes passing over each of the terrestrial facilities, searching for a communication route, selecting satellites to be passed through, and setting the times at which each satellite on the communication route transmits and receives information. Therefore, the conventional technology has a problem of complicated operation of the communication satellite system. Furthermore, the conventional technology has a problem of requiring the terrestrial facility to generate communication commands for the satellite based on the operation plan and transmit the generated communication commands to the satellite in orbit. According to this operational example, the longitudinal separation angle of the normal vectors of the first and second orbital planes is known, and therefore the position of the intersection between the first and second orbital planes is also known. Therefore, according to this operational example, when the first ground facility 90 communicates with the second ground facility 90 via the communications satellite system 10, the known position of the intersection between the first and second orbital planes is utilized, eliminating the need to travel via multiple orbital planes. Therefore, according to this operational example, communication between adjacent orbits can be achieved without complex communication route searches. Furthermore, according to this operational example, the load on the ground facilities can be reduced.

[0032] <Operation Example 2 According to Embodiment 1> This operation example is an extension of operation example 1 according to embodiment 1. In this operation example, the total number of orbital planes constituting the plurality of orbital planes is 12 or more, and the total number of satellites 30 flying on each of the plurality of orbital planes is 15 or more.

[0033] With the advent of supersonic glide missiles, it is no longer possible to deal with missiles by detecting their launch using satellites in geostationary orbit alone. Therefore, there is a strong demand for a missile tracking system using a constellation of low-orbit satellites. Surveillance directed toward the Earth's edge is also called limb surveillance, and limb surveillance allows the spacecraft to be monitored against the backdrop of space. This has the advantage that the body of the spacecraft, whose temperature has risen after the end of the thrust, can be monitored without error using infrared monitoring equipment. The information on flying objects acquired by low-earth orbit satellites must be transmitted to response assets quickly. For example, there has been a demand for a communications satellite system that can transmit satellite information quickly to ground equipment 90 located at 35 degrees north latitude and 140 degrees east longitude.

[0034] This operational example has the advantage of enabling satellite information to be quickly transmitted to the ground equipment 90. It also has the advantage of enabling a communication device between orbital planes with different normal vectors to be realized at a relatively low cost.

[0035] ***Other Configurations*** <Variation 1> In this embodiment, the functions of control unit 711 are realized by software. As a modified example, the functions of control unit 711 may be realized by hardware. Figure 12 shows this modified example.

[0036] The ground equipment 90 includes an electronic circuit 780 instead of the processor 710 . The electronic circuit 780 is a dedicated electronic circuit that realizes the functions of the control unit 711 . Specifically, the electronic circuit 780 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC (Integrated Circuit), a GA (Gate Array), an ASIC, or an FPGA. The functions of the control unit 711 may be realized by one electronic circuit, or may be realized by distributing the functions among a plurality of electronic circuits. As another modification, some of the functions of the control unit 711 may be realized by the electronic circuit 780, and the remaining functions may be realized by software.

[0037] The processor 710, the electronic circuit 780, the main memory device 720, and the auxiliary memory device 730 are collectively referred to as processing circuitry. That is, in the ground equipment 90, the functions of the control unit 711 are realized by the processing circuitry. The ground facilities 90 according to other embodiments may also have the same configuration as this modified example.

[0038] Embodiment 2 The following mainly describes the differences from the above-described embodiment with reference to the drawings.

[0039] ***Configuration Description*** 13 shows an example of the configuration of an edge computing system 11 according to this embodiment. The edge computing system 11 is made up of multiple satellites 30 flying in a target orbital plane, and also includes a main satellite 40. The edge computing system 11 may include any number of main satellites 40. The satellites 30 and the main satellite 40 form a circular communication network in the target orbital plane.

[0040] The satellite 30 according to this embodiment does not necessarily have to include the third communication device.

[0041] The configuration of the main satellite 40 is similar to that of the satellite 30, except that the main satellite 40 includes a computer 41 and an edge server 42. The main satellite 40 may implement the functions of the satellite 30. Each of the calculator 41 and the edge server 42 is a computer. The computer may be the same as the computer provided in the ground facility 90. The calculator 41 and the edge server 42 may be configured integrally as appropriate. The computer 41 executes the analysis process based on instructions from the ground equipment 90. At this time, the computer 41 receives data as needed from the ground equipment 90. The computer 41 also generates a transmission command, which is a command for communicating the result information to the ground equipment 90 and is a command for the satellite m. The edge server 42 stores orbital information for the satellites 30 and the main satellite 40 .

[0042] The ground facility 90 is ground facility that constitutes a data center or ground facility that is owned by a user. A specific example of the user is a customer who has a contract with the operator of the data center.

[0043] ***Explanation of Operation*** <Operation Example 1 According to Embodiment 2> An example of the operation of the edge computing system 11 will be described below. First, the computer 41 generates result information by executing an analysis process. Next, the computer 41 selects a satellite that passes over the ground facility 90 from among multiple satellites as satellite m based on the orbit information stored in the edge server 42, and derives the time Tm0 at which satellite m passes over the ground facility 90. Here, the satellite 30 and the main satellite 40 may be collectively referred to as "satellite." Next, the main satellite 40 transmits the result information to the satellite m through the ring communication network. Next, the satellite m transmits the result information to the ground equipment 90 at time Tm0.

[0044] In this operation example, the main satellite 40, which is equipped with the edge server 42 and performs edge computing, generates a communication command for the ground facility 90 for a satellite flying in a target orbital plane before transmitting the generated result information to the ground facility 90. The main satellite 40 then transmits the generated communication command to the satellite flying in the target orbital plane via a circular communication network. Even if the ground facility 90 is located directly below the target orbital plane, the time at which a satellite flying in the target orbital plane passes over an individual ground facility 90 depends on its flight position within the orbital plane. Therefore, the main satellite 40 derives the time Tm0 at which satellite m passes over an individual ground facility 90 based on the satellite orbit information stored in the edge server 42, and generates a communication command.

[0045] According to this operation example, the main satellite 40 generates communication commands in orbit, which has the effect of reducing the load on the ground, which has traditionally been generated on the ground, for command generation, command transmission, creation of communication operation plans, and control, at the ground equipment 90. Furthermore, according to this operation example, the main satellite 40 is considered to be an IoT (Internet of Things), and is equipped with a computer 41 and an edge server 42. Furthermore, each satellite 30 can communicate satellite information with a ground facility 90 constituting a data center via a circular communication network. Therefore, according to this operation example, there is an advantage that each satellite 30 and the ground facility 90 can quickly communicate with the edge server 42 equipped in the main satellite 40. Furthermore, according to this operation example, the results of calculation processing on orbit can be directly transmitted to the user's ground equipment 90. This has the effect of reducing the burden on the ground equipment 90 equipped with a data center.

[0046] Embodiment 3 The following mainly describes the differences from the above-described embodiment with reference to the drawings.

[0047] ***Configuration Description*** The configuration of the edge computing system 11 according to this embodiment corresponds to a combination of the communications satellite system 10 according to embodiment 1 and the edge computing system 11 according to embodiment 2. That is, the edge computing system 11 is made up of a plurality of orbital planes. Among the satellites constituting the edge computing system 11 is a main satellite 40. The main satellite 40 may fly in each of two or more orbital planes. The edge server 42 stores orbital information of each satellite 30 constituting the edge computing system 11 and the main satellite 40.

[0048] The computer 41 included in the main satellite 40 generates a command related to at least one of transmission and reception. The computer 41 may also search for a communication route between the main satellite 40 and each satellite including an information collection device, using an inference model that has learned the relationship between the constellations of satellites in the edge computing system 11 and the communication routes between the satellites that make up the edge computing system 11, and information indicating the constellations of the multiple satellites that make up the edge computing system 11. The computer 41 may also predict the movement path of a target moving object, using an inference model that has learned the relationship between information about the moving object collected by the information collection device and the movement path of the moving object corresponding to the information collected by the information collection device, and target moving object information. Here, the information collection device is a device that collects information outside the satellite. The target moving object information is information about the target moving object collected by the information collection device. The target moving object is a moving moving object. The main satellite 40 is a satellite flying in the orbital plane in which the main satellite 40 is flying, and transmits command signals to satellites passing near the intersection of the orbital plane in which the main satellite 40 is flying and another orbital plane via a circular communication network formed in the orbital plane in which the main satellite 40 is flying.

[0049] ***Explanation of Operation*** <Operation Example 1 According to Embodiment 3> 14 is a diagram for explaining this operation example, which will be described with reference to FIG. First, the computer 41 generates result information by executing an analysis process. Next, the computer 41 selects an orbital plane that passes over the ground facility 90 from among a plurality of orbital planes other than the main satellite orbital plane, as an overflight orbital plane, based on the orbital information stored in the edge server 42. Here, the main satellite orbital plane is the orbital plane in which the main satellite 40, which includes the computer 41, is flying. After that, the computer 41 derives an overflight time, which is the time when the overflight orbital plane passes over the ground facility 90. Note that the overflight time may be a certain time period. Next, the computer 41 derives the position of the target intersection, which is the intersection formed by the main satellite orbital plane and the overhead passing orbital plane in a planar view, based on the orbital information stored in the edge server 42. Next, the main satellite 40 shares the result information with other satellites flying in the main satellite orbital plane through a circular communication network formed in the main satellite orbital plane. Next, the first communication satellite transmits the result information to a second communication satellite in the vicinity of the target node, where the first communication satellite is one of a plurality of satellites flying in the primary satellite orbital plane, and the second communication satellite is one of a plurality of satellites flying in the overhead passing orbital plane. Next, the second communication satellite transmits the result information to the third communication satellite through a circular communication network formed in the overpassing orbital plane. Here, the third communication satellite is a satellite flying in the orbital plane and passing over the ground facility at the overpass time. Note that the second communication satellite and the third communication satellite may be the same satellite, in which case the second communication satellite does not transmit the result information to the third communication satellite. Next, the third communications satellite transmits the result information to the ground facility 90 at the time of passing over the sky.

[0050] In this operation example, the rotation of the orbital planes around the Earth is not synchronized with the rotation of the Earth. Therefore, the time during which a satellite in a specific orbital plane passes over a specific ground facility 90 is limited. Therefore, by providing multiple orbital planes with dispersed longitude components of the normal vectors, the number of orbital planes passing over any ground facility 90 is increased, thereby increasing the time during which any ground facility 90 can communicate with any satellite. If the edge computing system 11 has a sufficient number of orbital planes and a sufficient number of satellites so that any ground facility 90 can communicate with any satellite in any orbital plane at any time, a constant communication environment is created. In this case, in order to transmit result information generated by the main satellite 40 in a specific orbital plane to any ground facility 90, the result information can be transmitted to a satellite in an orbital plane passing above the ground facility 90 at a specific time, and the satellite passing above the ground facility 90 can then transmit the result information to the ground facility 90.

[0051] <Operation Example 2 According to Embodiment 3> This operation example corresponds to an operation example obtained by expanding the operation example 1 according to the third embodiment. In this operation example, the first communication satellite transmits the result information to the second communication satellite in the vicinity of the target node when the direction of travel of the first communication satellite at the target node is closer to the target direction than the direction of travel of the second communication satellite at the target node. The target direction is specifically north.

[0052] In an edge computing system 11 having a main satellite 40 for each orbital plane, it is necessary to determine the timing for sending and receiving result information and the satellites from which to send and receive it by prioritizing the orbital planes or by prioritizing the orbital relative positions. Near the two intersection points formed at the orbital altitude of the intersection line of two orbital planes with orbital inclination angles, satellites flying north from the southern hemisphere to the northern hemisphere and satellites flying south from the northern hemisphere to the southern hemisphere pass. Therefore, as an example, if the satellite flying north from the southern hemisphere to the northern hemisphere is the transmitting side and the satellite flying south from the northern hemisphere to the southern hemisphere is the receiving side, a system can be constructed in which the satellite flying north 30 has priority. In this case, the direction of travel of the satellite flying north is closer to the north than the direction of travel of the satellite flying south. Note that the transmitting side and the receiving side may be reversed. Furthermore, if the satellites flying in both orbital planes near the intersection point are either flying north or flying south, it is important to note that the orbital inclination angles of the two orbital planes are different from each other.

[0053] <Operation Example 3 According to Embodiment 3> This operation example corresponds to an operation example obtained by expanding any of the operation examples described above according to the third embodiment. In this operation example, a priority regarding the transmission order is set for each of the plurality of orbital planes.

[0054] The premise of this operation example will be explained. A main satellite 40 flies on each of orbital planes α and β, which are orbital planes that make up multiple orbital planes. A computer 41 provided in the main satellite 40 flying on orbital plane α generates result information αR as result information. A computer 41 provided in the main satellite 40 flying on orbital plane β generates result information βR as result information. Any one of the multiple satellites flying on orbital plane α transmits the result information αR to any one of the multiple satellites flying on orbital plane β. Any one of the multiple satellites flying on orbital plane β transmits result information βR to any one of the multiple satellites flying on orbital plane α. First, we will explain the operation when the priority set for the orbital plane α is higher than the priority set for the orbital plane β. In this case, before any one of the multiple satellites flying in the orbital plane β transmits the result information βR to any one of the multiple satellites flying in the orbital plane α, any one of the multiple satellites flying in the orbital plane α transmits the result information αR to any one of the multiple satellites flying in the orbital plane β. Next, we will explain the operation when the priority set for the orbital plane α is lower than the priority set for the orbital plane β. In this case, after one of the multiple satellites flying in the orbital plane β transmits the result information βR to another of the multiple satellites flying in the orbital plane α, one of the multiple satellites flying in the orbital plane α transmits the result information αR to another of the multiple satellites flying in the orbital plane β.

[0055] By determining the priority of the orbital planes in advance, a default priority for communication when a satellite passes near the intersection of the orbital planes is determined. However, the result information generated by the main satellite 40 flying in an orbital plane with a relatively low priority may be transmitted via an orbital plane with a relatively high priority. Therefore, when transmitting data from a satellite flying in an orbital plane with a relatively high priority to a satellite flying in an orbital plane with a relatively low priority, it is reasonable for both satellites to share a communication procedure between the orbital planes.

[0056] <Operation Example 4 According to Embodiment 3> This operation example corresponds to an operation example obtained by expanding any of the operation examples described above according to the third embodiment. In this operation example, when a plurality of main satellites 40 are flying in the orbital plane that constitutes the edge computing system 11, a priority order regarding the transmission order is set for each of the plurality of main satellites 40.

[0057] In an edge computing system 11 in which multiple main satellites 40 equipped with at least one of an edge server 42 and a computer 41 equipped with AI (Artificial Intelligence) exist in the same orbital plane, there is a risk of disruption to the communication network if each main satellite 40 communicates with a satellite flying in another orbital plane without cooperation. Therefore, it is possible to determine the priority of the main satellites 40 for each orbital plane in advance, and when inter-orbit communication between multiple main satellites 40 and a specific orbital plane overlaps, the main satellite 40 that is set with a relatively high priority among the multiple main satellites 40 can manage the transmission of result information from the other main satellites 40 in the same orbital plane. By having the main satellite 40, which is set to a relatively high priority, execute the above-mentioned process, there is an advantage that disruption of the communication network can be avoided.

[0058] <Operation Example 5 According to Embodiment 3> This operation example corresponds to an operation example obtained by expanding any of the operation examples described above according to the third embodiment. In this operation example, any of the satellites constituting the edge computing system 11 is equipped with an information collection device. Here, the information collection device equipped on the satellite may be an image information collection device, a radio wave information collection device, or a space environment monitor information collection device. The image information collection device may be an optical monitoring device that acquires visible images, a synthetic aperture radar that acquires radio wave images, or an infrared monitoring device that visualizes temperature information.

[0059] <Operation Example 6 According to Embodiment 3> This operation example corresponds to an operation example obtained by expanding operation example 5 according to the third embodiment. In this operation example, each of the two or more satellites that make up the edge computing system 11 is equipped with an information collection device. The edge server 42 stores a flight path model. The flight path model is used to estimate the flight path of a flying object, which is a moving object. The flight path of a flying object corresponds to the movement path of the moving object. The information gathering device is an infrared monitoring device and generates flying object detection information, which indicates the results of detecting flying objects. Each satellite equipped with an information gathering device shares flying object detection information with each satellite equipped with an information gathering device and the main satellite 40 by communication through a circular communication network formed on each of the multiple orbital planes and communication near the intersection formed by two different orbital planes of the multiple orbital planes in a planar view. The computer 41 predicts the flight path of the flying object using the flying object detection information and a flight path model stored in the edge server 42, and generates an information acquisition command. The information acquisition command is a command to a satellite equipped with an information collection device, and is a command to acquire information about the flying object. The main satellite 40 transmits information acquisition commands to each satellite equipped with an information collection device by communication through a circular communication network formed on each of the multiple orbital planes and by communication near the intersection formed by two different orbital planes of the multiple orbital planes in a planar view.

[0060] The edge computing system 11 may execute the process of the above-described operation example using machine learning. Machine learning will be described below. Machine learning can be divided into supervised learning, which is optimized by inputting a teacher signal (correct answer), and unsupervised learning, which does not require a teacher signal. As a specific example, by generating an inference model by learning in advance the type of flying object, the type of propellant, and a number of typical flight patterns as a teacher model, it becomes relatively easy and quick to perform inference using actual measurement data of a flying object whose launch is detected by an information collection device and whose trajectory information is acquired. Here, the computer 41 uses the inference model to predict the flight path of the flying object and estimate the landing position of the flying object. However, in order to predict the flight path of a flying object whose flight direction is unknown at the stage of launch detection, it is necessary to track and monitor the flying object using a subsequent monitoring satellite. Here, the monitoring satellite is a satellite equipped with an information gathering device. Therefore, in order to transmit the launch detection information to the subsequent monitoring satellite, the launch detection information must be routed through a communication network formed by a group of communication satellites. Here, in a communication network using a communication satellite constellation, the flight positions of the communication satellites change constantly. Therefore, the monitoring satellite must search for the optimal communication route and determine the ID (Identification) of the communication satellite that will exchange the flying object information and the time to exchange the launch detection information. This also applies to the exchange of flying object information between a monitoring satellite and a communication satellite. Note that a monitoring satellite may also have the functionality of a communication satellite. When the search for the optimal communication route is performed by the ground facility 90, it is necessary to send commands to each of the monitoring satellite and the communication satellite, indicating the time for sending and receiving the flying object information and the satellite ID. However, in this case, the communication network for sending the commands becomes an issue. Therefore, it is reasonable for the main satellite 40 to be equipped with an analysis device using machine learning, search for an optimal communication route in orbit, generate communication commands, and transmit the generated communication commands to each satellite that makes up the searched optimal communication route. The analysis device is typically a computer 41. An effective method for searching for an optimal communication route is to use an algorithm known as the Dijkstra algorithm. Note that the weight of each route does not change in the static Dijkstra algorithm. However, in a communication network formed by a communication satellite constellation, the weight of each communication route changes as the flight position of the communication satellite changes, i.e., the weight of each communication route changes with time. Therefore, for each communication satellite that searches for an optimal communication route while updating its orbital information, the communication satellite that receives flight information may search for an optimal communication route and transmit the flight information to the next communication satellite. In other words, each satellite 30 may be equipped with a computer 41. Furthermore, the computer 41 may generate an inference model that infers an optimal communication route by inputting information indicating the satellites at the start and end of communication and information indicating the satellite positions in the edge computing system 11, based on previously searched optimal communication routes and the satellite positions at the time the optimal communication route was searched.

[0061] In addition, there are known methods for route search: breadth-first search and depth-first search. For launch detection information, a breadth-first search prioritizes transmitting the missile information to the communication network as quickly as possible, and subsequent satellites then repeat the tracking. However, once the missile's flight direction can be roughly estimated, it is reasonable to perform a depth-first search.

[0062] In the flying object tracking system, the flying object is tracked and monitored by repeating the flight path prediction using the above-mentioned machine learning and the search for communication routes using Dijkstra's algorithm, and the final landing position of the flying object is inferred.

[0063] Furthermore, as a specific example, the computer 41 generates an inference model by performing machine learning using past results of tracking and monitoring of the flying object after repeatedly tracking and monitoring the flying object, and by performing deep learning using examples of flying object behavior that do not match the multiple flying object models used as training models. Here, the results of tracking and monitoring the flying object consist of information collected by the information collection device and information indicating the flying object's flight path. This improves the prediction accuracy and speeds up the prediction of the flying object's flight path.

[0064] In addition, the flight direction and flight distance of a projectile launched from a mobile launch platform (TEL) or other similar device, rather than from a fixed launch pad, differ from the flight direction and flight distance of a projectile indicated by a typical flight model. Therefore, it is effective to correct the projectile's trajectory model by performing deep learning using actual measurement data of the projectile.

[0065] This operational example has the effect of enabling satellite information to be quickly shared between satellites. Note that the edge computing system 11 according to this operational example may be configured to transmit information obtained by infrared monitoring on orbit using edge computing to track a flying object called a supersonic gliding missile, to another satellite equipped with an infrared monitoring device.

[0066] <Operation Example 7 According to Embodiment 3> This operation example corresponds to an operation example obtained by expanding operation example 5 or operation example 6 according to the third embodiment. In this operation example, the information gathering device is a synthetic aperture radar or an optical monitoring device, and has the function of tracking and monitoring a moving object, which is specifically a ship.

[0067] According to this operation example, when tracking a ship sailing on the ocean using a synthetic aperture radar or an optical surveillance device, the sharing of surveillance information between different orbits has the effect of enabling the ship to be tracked quickly and with a low risk of being lost.

[0068] ***Other embodiments*** The above-described embodiments may be freely combined, or any of the components in each embodiment may be modified, or any of the components in each embodiment may be omitted. Furthermore, the embodiments are not limited to those shown in Embodiments 1 to 3, and various modifications are possible as necessary. The procedures explained using the drawings and the like may be modified as appropriate. [Explanation of symbols]

[0069] 10 Communications satellite system, 11 Edge computing system, 20 Satellite constellation, 30 Satellite, 31 Satellite control device, 32 Communication device, 33 Propulsion device, 34 Attitude control device, 35 Power supply device, 40 Main satellite, 41 Computer, 42 Edge server, 90 Ground equipment, 91 Satellite control device, 710 Processor, 711 Control unit, 720 Main memory device, 730 Auxiliary memory device, 740 Input interface, 750 Output interface, 760 Communication interface, 770 Signal line, 780 Electronic circuit, 810 Ground communication device.

Claims

1. An edge computing system consisting of a plurality of satellites flying in a target orbital plane, Each of the plurality of satellites is designated as a target satellite, and the target satellite is a satellite flying in the target orbital plane, and the target satellite is equipped with a first communication device that communicates with satellites located ahead and behind the target satellite in the direction of travel, and a second communication device that communicates with ground equipment installed on the ground, the plurality of satellites form a circular communication network, any one of the plurality of satellites is a primary satellite having a computer and an edge server storing orbital information of each of the plurality of satellites; The computer Generate result information by performing an analysis process; Selecting a satellite that passes over the ground facility from among the plurality of satellites as a satellite m based on the orbit information stored in the edge server, and deriving a time Tm0 at which the satellite m passes over the ground facility; The main satellite transmits the result information to the satellite m through the ring communication network; The satellite m transmits the result information to the ground equipment at the time Tm0.

2. The primary satellite of claim 1 .

Images